In-service failures of metal implanted appliances used in orthopedic medical applications are being investigated as to cause and prevention. Improvement in the metal by fabricational changes in casting, by use of sintering, hot isostatic pressing and heat treatment are being devised. BIBLIOGRAPHIC REFERENCES: DEVINE, T.M. and WULFF J.: Cast vs Wrought Co Cr Mo C Surgical Implant Alloys. J. Biomed. Research, 10: 151, 1976.